In recent years, treatment of a lumen such as a blood vessel or a body cavity using a catheter has been performed frequently since such a treatment has very low surgical stress. For example, a catheter which is selectively introduced into a complicatedly branched blood vessel in the body is, generally, selectively pushed in to the blood vessel along a guide wire that is previously introduced into the blood vessel. A medicine for treatment, a contrast medium for diagnosis, or the like is accordingly transferred from the operator side (proximal end side) to a distal end side. Therefore, an elongated catheter tube constituting the catheter has large inner and outer diameters in the proximal end side which enhances sufficient stiffness to provide sufficient pushability and also provides injection characteristics of a medicine or a contrast medium. Also, the elongated catheter tube has smaller inner and outer diameters on the distal end side than those on the proximal end side, which gives flexibility to improve accessibility to a peripheral blood vessel and followability to the guide wire.
An example of a method of producing such a catheter tube is described in Japanese Patent Application Laid-Open No. 2008-183226. In this method, a thermoplastic resin is coated and formed on a core rod which is constituted with thick portions and thin portions continuously aligned with a given space in between. A plurality of catheter tubes is formed as a continuous body on the same core rod. The continuous body is severed together with the core rod into individual catheter tubes. The core rod is then removed by pulling-out the rod, thus producing the catheter tube.
A hub (proximal end connecting part) which functions as an insert port into a lumen for a guide wire, an injection port into a lumen for a liquid medicine, an embolus material, a contrast medium, or the like, and a gripping part used to operate a catheter tube, may be connected to a proximal end portion of the catheter tube. However, there is no discussion about a hub in Japanese Patent Application Laid-Open No. 2008-183226 mentioned above, which means that a hub needs to be installed to each catheter tube after each catheter tube is severed from a continuous body constituted of a plurality of catheter tubes.